Method for continuous aggregation of pre-toner particles

Abstract

A method for the continuous aggregation of pre-toner particles including continuously flowing a slurry that includes at least one resin, and optionally includes other components used in forming aggregated pre-toner particles, or continuously flowing individual dispersions of the components of the slurry, into a reactor. The reactor includes a cylinder with a cylindrical channel, a mixing shaft located in the cylindrical channel, a longitudinal axis of the mixing shaft is substantially parallel to a longitudinal axis of the cylinder, at least one blade that has a plurality of holes is attached to the mixing shaft. The slurry or the dispersions are continuously mixed to form aggregated pre-toner particles.

What is claimed is: 
     
       1. A method for the continuous aggregation of pre-toner particles, the method comprising:
 continuously flowing a slurry that comprises at least one component that includes at least one resin, and optionally further includes at least one wax, at least one colorant, at least one buffer, at least one chelating agent, at least one coagulant, and/or at least one surfactant, or continuously flowing individual dispersions of the components of the slurry, into at least a first reactor comprising:
 a cylinder,
 wherein the cylinder has a cylindrical channel, wherein
 the cylindrical channel has an inner wall; 
 
 
 a mixing shaft located in the cylindrical channel, wherein
 a longitudinal axis of the mixing shaft is substantially parallel to a longitudinal axis of the cylinder; and 
 
 at least one blade attached directly to the mixing shaft, wherein
 the at least one blade has a plurality of holes, and 
 
 
 continuously mixing the slurry or the individual dispersions of the components of the slurry, in the reactor to form aggregated pre-toner particles; and 
 continuously collecting the aggregated pre-toner particles. 
 
     
     
       2. The method of  claim 1 , wherein the aggregated pre-toner particles have a GSDn is in the range of about 1.15 to about 1.5. 
     
     
       3. The method of  claim 1 , wherein the after the aggregated pre-toner particles are formed, the aggregated pre-toner particles are subjected to at least one further processing step selected from the group consisting of freezing particle aggregation, chelation, coalescence, washing, drying, and toner blending in order to form toner particles. 
     
     
       4. The method of  claim 1 , wherein a length aspect ratio (length/diameter) of the reactor is from about 5 to about 50. 
     
     
       5. The method of  claim 1 , wherein a D 50  average particle size of the aggregated pre-toner particles exiting the at least one reactor is from about 1 to about 1000 times larger than a D 50  average particle size of the slurry, or the individual dispersions of the components of the slurry, entering the reactor. 
     
     
       6. The method of  claim 1 , wherein a space-time yield of the continuous aggregation method is about 0.1 g/L/hr to about 3,000 g/L/hr. 
     
     
       7. The method of  claim 1 , wherein the diameter or width the mixing shaft is about 5% to about 95% of the diameter of the inner wall. 
     
     
       8. The method of  claim 1 , wherein the mixing shaft has an eccentric axis of rotation relative to a centerline axis of the inner wall, or the mixing shaft is located at the center of the cylindrical channel. 
     
     
       9. A process for the continuous production of emulsion aggregated pre-toner particles, the process comprising:
 continuously feeding a slurry comprising at least one resin into at least one agitated plug-flow reactor comprising at least one entry point, at least one exit point, and an impeller comprising at least one perforated blade; 
 continuously aggregating the slurry in the at least one agitated plug-flow reactor to form aggregated particles; and 
 continuously withdrawing from the at least one exit point of the at least one agitated plug-flow reactor a stream that comprises the aggregated particles, wherein
 the average particle size of the aggregated particles is about one to about four orders of magnitude greater than the average particle size of the feed dispersion. 
 
 
     
     
       10. The method of  claim 9 , wherein the slurry is a homogenous slurry, and further comprises at least one wax, at least one colorant, at least one buffer, at least one chelating agent, at least one coagulant, and/or at least one surfactant. 
     
     
       11. The method of  claim 9 , wherein the slurry is a nonhomogeneous slurry, and further comprises at least one wax, at least one colorant, at least one buffer, at least one chelating agent, at least one coagulant, and/or at least one surfactant. 
     
     
       12. The method of  claim 9 , wherein a space-time yield of the process ranges from about 0.1 g/L/hr to about 3,000 g/L/hr. 
     
     
       13. The method of  claim 9 , wherein a residence time of the mixture in the at least one reactor is from about 2 to about 60 minutes. 
     
     
       14. The method of  claim 9 , wherein the aggregation of the slurry occurs in one rector. 
     
     
       15. A method for the continuous aggregation of pre-toner particles, the method comprising:
 continuously flowing a slurry that comprises at least one component that includes at least one resin, or continuously flowing individual dispersions of the components of the slurry, into at an input end of least one reactor comprising: 
 a hollow tube, wherein
 the hollow tube has a cylindrical inner wall; 
 a length of the tube is greater than a diameter of the tube; 
 
 a mixing shaft, wherein
 the mixing shaft is concentric with the hollow tube, 
 a longitudinal axis of the mixing shaft is parallel to a longitudinal axis of the hollow tube, and 
 the mixing shaft is rotatable about the longitudinal axis of the mixing shaft, 
 
 a least one perforated blade, wherein
 the at least one perforated blade is attached to the mixing shaft, and 
 the at least one perforated blade extends radially from the mixing shaft toward the inner wall of the tube, 
 
 continuously rotating the mixing shaft in the at least one reactor to continuously at least partially aggregate the mixture into at least partially aggregated pre-toner particles; and 
 continuously flowing the at least partially aggregated pre-toner particles out of the at least one reactor through an output end of the at least one reactor. 
 
     
     
       16. The method of  15 , wherein the at least one reactor comprises at least a first and second reactor, wherein the output end of the first reactor is in fluid connection with an input end of the second reactor, and the slurry or the individual dispersions are partially aggregated in the first reactor, and the method further comprises:
 continuously flowing the partially aggregated pre-toner particles out of the output end of the first reactor and into the input end of the second reactor; 
 continuously further aggregating the partially aggregated pre-toner particles in the second reactor into further aggregated pre-toner particles, and 
 continuously flowing the further aggregated pre-toner particles out of the second reactor through an output end of the second reactor. 
 
     
     
       17. The method of  claim 15 , wherein the mixing shaft in the first reactor and in the second reactor are rotated at different speeds. 
     
     
       18. The method of  15 , wherein the at least the partially aggregated pre-toner particles are further aggregated in a series of continuously-stirred-tank-reactors or in batch reactor. 
     
     
       19. The method recited in  claim 15 , wherein the at least one reactor comprises at least a first and second reactor, wherein the output end of the first reactor is in fluid connection with an input end of the second reactor, and the method further comprises:
 continuously aggregating the slurry, or the individual dispersions of the components of the slurry, into fully aggregated pre-toner particles in the first reactor; 
 continuously flowing the fully aggregated pre-toner particles out of the at least one reactor through the output end of the at least one reactor and into the input end of the second reactor; 
 simultaneously continuously flowing a homogenous mixture of shell latex particles into the input end of the second reactor; 
 mixing the fully aggregated pre-toner particles and the homogenous mixture of shell latex particles to form core-shell pre-toner particles; and 
 continuously flowing the core-shell pre-toner particles out of the second reactor through an output end of the second reactor. 
 
     
     
       20. The method recited in  claim 15 , wherein the at least one reactor comprises at least a first series of reactors to aggregate the slurry, or aggregate the individual dispersions of the components of the slurry, into fully aggregated pre-toner particles, and at least a second series of reactors to apply a latex shell to the fully aggregated pre-toner particles, wherein the method further comprises,
 continuously flowing the fully aggregated pre-toner particles from the first series of reactors into the second series of reactors, and 
 simultaneously continuously flowing a homogenous mixture of shell latex particles into the second series of reactors; 
 mixing the fully aggregated pre-toner particles and the homogenous mixture of shell latex particles to form core-shell pre-toner particles; and 
 continuously flowing the core-shell pre-toner particles out of the second series of reactors.